Implementation and evaluation of change-over speed in plug-in hybrid electric two wheeler Shaik Amjad a, * , R. Rudramoorthy b , P. Sadagopan b , S. Neelakrishnan b a Department of Automobile Engineering, VNR Vignana Jyothi Institute of Engineering and Technology, Hyderabad, India b PSG College of Technology, Coimbatore, 641 004, India article info Article history: Received 26 August 2014 Received in revised form 4 April 2016 Accepted 9 May 2016 Keywords: Plug-in hybrid electric two wheeler Urban air quality Fuel economy Control strategy Change-over speed City driving pattern abstract In Asia, two wheelers are popular mode of transportation to a large group of people because of their relative affordability and ability to maneuver in heavy city traffic. However, the rate of fuel consumption and emission contribution by them, especially in urban areas need more attention to improve sustain- ability of energy and air quality. Recently, plug-in hybrid technology has been emerged as one of the most promising alternatives in reducing petroleum consumption and emission. This paper presents the implementation of plug-in hybrid technology on a two wheeler by formulation of novel control strategy suitable for Indian city driving needs. Experimental investigations on hub motor and IC (internal com- bustion) engine has been carried out to fix the change-over speed in hybrid mode, followed by road test on prototype vehicle. The performance of prototype vehicle on IDC (Indian driving cycle) simulated road pattern and actual road driving, confirmed the change-over speed of vehicle in hybrid mode. The con- verted plug-in hybrid electric two wheeler also demonstrated the drive strategy adopted for higher energy efficiency up to 2.5 times. So, plug-in hybrid electric two wheelers show significant improve- ments in fuel economy by replacing petroleum fuel with electricity for portions of trip to achieve nations' energy security. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Two-wheelers play a very important role in providing personal transportation in most of the cities in Asia for carrying of one or two passengers and help to alleviate traffic congestion. India has the second highest two-wheeler population in the world and it is ex- pected that country's two-wheeler population exceed China's before 2020 [1]. Statistics show that the two wheeler population in India has grown very rapidly in the last decade and account for more than 76% of the Indian vehicle population [2]. The high levels of pollutants emitted by these vehicles are mainly responsible for respiratory ailments including lung cancer, asthma, etc. In addition, the emission profile of two wheelers depends on the type of engine that powers them, either 2-stroke or 4-stroke. Because of their limited use of emission control strategies, they are emerging as largest source of urban air pollution. Hence, there is a need to develop a two wheeler with great potential to reduce urban emissions and overall petroleum consumption. Battery operated EVs (electric vehicles) with zero tail-pipe emission are considered as one of the alternative drivetrain op- tions. However, these vehicles have not been successful because of higher cost, added weight of batteries, reduced load capacity, limited range and lack of recharging infrastructure [3]. Followed by, advent of HEVs (hybrid electric vehicles) offer fuel economy improvement capacity by using an electric motor to reduce the fluctuating energy requirements of the internal combustion engine, but, they entirely depend on petroleum fuels [4]. Recently, plug-in hybrid electric vehicles gained a momentum, which offers most of the environmental benefits of electric vehicle operation without giving up the advantages of an IC (internal combustion) engine based vehicle, such as the ability to refuel if necessary [5]. PHEV (Plug-in hybrid electric vehicle) is a hybrid electric vehicle with ability to plug-in to grid electricity and has the potential to displace a significant portion of transportation petroleum consumption by using electricity for portions of trip [6]. One of the unique advan- tages of plug-in hybrid vehicles is their capability to integrate the transportation and electric power generation sectors in order to improve the efficiency, fuel economy and reliability of both systems [7]. The plug-in hybrid electric vehicles are the right move towards * Corresponding author. E-mail address: amjad72@gmail.com (S. Amjad). Contents lists available at ScienceDirect Energy journal homepage: www.elsevier.com/locate/energy http://dx.doi.org/10.1016/j.energy.2016.05.025 0360-5442/© 2016 Elsevier Ltd. All rights reserved. Energy 109 (2016) 858e865